1. Field of the Invention
The present invention relates to a single-lens reflex camera.
2. Description of the Related Art
Japanese Patent Laid-Open No. (“JP”) 6-308375 discloses a single-lens reflex camera that includes two light-shielding walls unparallel (not parallel) to an image-pickup plane between an expected imaging surface of an image-pickup lens and the bottom of a mirror box, and improves the focus detection accuracy by preventing stray light from entering a focus detection unit using these light-shielding walls. The bottom of the mirror-box has an opening that introduces a focus detecting light flux to the focus detecting unit, and the bottom of the mirror box has a plane parallel to an optical axis in light of the drawings of JP 6-308375.
According to JP 6-308375, an attempt to approach the focus detecting unit to the optical axis of the image-pickup lens in order to miniaturize the camera would cause the bottom of the mirror box to move up, and the flare reflected on the bottom of the mirror box to enter the image-pickup plane, hindering high-quality image pickup. In addition, when the bottom of the mirror box has a plane parallel to the optical axis, a dead space becomes wider around the focus detecting unit under it and the miniaturization becomes difficult.